Color display devices are typically multi-channel devices in the sense that multiple physical color channels represent every pixel on the display. Multi-channel display devices include cathode ray tubes (CRT), liquid crystal displays (LCD), plasma displays, and other imaging devices. One common example of a multi-channel device is a three channel device comprising red, green, and blue (RGB) channels.
Each of the color channels in a multi-channel display device may be modeled as a combination of a light source and a light valve. In the case of the LCD, the light source comprises a common backlight and color filters for each of the channels. The light valve, in the case of an LCD, typically comprises one or two fixed polarizers and liquid crystal cells (LCC), which rotate a polarization plane of passing light to regulate the amount of light emitted from the display.
An individual emission spectrum for each of the color channels is useful for spectral modeling and display calibration to improve color accuracy of imagery presented by the display. However, the emission spectrum for a single color channel cannot be accurately measured, because the emission spectrum measurement includes light leakage from adjacent color channels.